The NTSB blamed the pilot for the accident and listed alcohol impairment as a contributing factor.
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X33897&key=1
That finding may be in dispute. Click below for letter that ran in L.A. Times 11/01/87:
http://articles.latimes.com/1987-11-01/local/me-17860_1_bruce-wayne-autopsy-report-orange-county-crime-laboratory-garden-grove
That said, I'm not defending Bruce Wayne, simply reliving the "glory days" when Bruce was the undisputed king of L.A. traffic reporters and the most famous pilot to fly out of "Maynard Farmer Airport," I mean, Fullerton.